Automotive engine valves are manufactured, for example, by molding a valve main body at a stem tip portion of which a head portion in a predetermined shape is integrally formed by primary forging and secondary forging, and then performing heat treatment such as annealing and nitriding. Then, among the manufactured valves, only ones that have satisfied all inspection criteria through various inspection processes for inspections of the stem straightness, the head thickness, the overall length, and the stem diameter, the presence of a leak in the face of a head portion, the presence of a crack in the head face, etc., are shipped as products.
The following Patent Literature 1 describes “Inspecting apparatus for beer barrel cap” in which beer barrels being workpieces are placed on a feed conveyor laid in a line form and fed and a cap inspection device, an inspection device for gas valves, and an inspection device for beer valves are sequentially provided along the feed conveyor (workpiece feed path) to perform inspections for the beer barrels sequentially.
Further, valve inspection equipment that sequentially performs various inspections for manufactured automotive engine valves also has a structure for which inspection devices corresponding to the respective inspections are disposed along a valve feed path laid in a line form, for example, in a manner of a stem straightness inspection process to a head thickness and overall length inspection process to a stem diameter inspection process to a leak inspection process, to perform inspections for the valves sequentially.